1. Field of the Invention
The present invention relates to a dividable tablet and to a press-through pack and, more specifically, to a dividable tablet which can be divided easily and accurately without being chipped and has excellent impact resistance and such a shape that does not cause the twining of the tablets in the film-coating step and to a press-through pack for containing the same which enables the dividable tablets contained therein to be divided into two easily and simply while they are contained in the press-through pack and all the divided tablets to be taken out at a time.
2. Description of the Related Art
A dividable tablet is divided by a pharmacist at the time of preparation according to dosage or by a patient himself when he takes it and has been developed to optimize the management of dosage for each individual patient and improve prescription ease.
A dividing line (dividing groove) is generally formed in this dividable tablet to divide the tablet.
FIGS. 13A, 13B and 13C are schematic diagrams of a flat dividable tablet of the prior art. FIG. 13A is a plan view, FIG. 13B is a bottom view and FIG. 13C is a side view.
This flat dividable tablet Te has a flat upper surface Sa and a flat lower surface Sb and a dividing line Ld is formed on the upper surface SA along a center line thereof.
To divide the dividable tablet Te into two, two areas R1 and R2 defined by the dividing line Ld on the upper surface Sa are held with the fingers of a pharmacist, patient or the like directly and the dividable tablet Te is divided along the dividing line Ld by spreading wide the dividing line Ld.
However, the dividable tablet Te shown in FIGS. 13A to 13C has such a problem that great force is needed to divide it into two so that it is difficult for a person of advanced age who suffers from a reduction in the strength of his fingers and a reduction in sensibility to divide the dividable tablet Te.
FIGS. 14A to 14C are schematic diagrams of a KARATE SHAPE dividable tablet of the prior art disclosed by Japanese Patent Application Laid-open No. Sho 61-289027. FIG. 14A is a plan view, FIG. 14B is a bottom view and FIG. 14C is a side view.
The KARATE shape tablet Tf has a flat lower surface Sb. A dividing line Ld is formed on an upper surface Sa along a center line thereof and two areas R1 and R2 defined by the dividing line Ld on the upper surface Sa have an inclined plane surface which ascends from lines Ld2 and Ld2 which are the borders of the dividing line Ld toward the periphery of the tablet so that the thickness of the tablet increases toward the periphery of the tablet.
To divide the dividable tablet Tf into two, a pharmacist, patient or the like holds the two areas R1 and R2 with fingers directly and divides it into two along the dividing line Ld. Alternatively, the dividable tablet Tf can be divided into two by placing the tablet upside down and pressing it down from above.
A tablet may contain a component having unpleasant smell or taste or a component which has poor stability against light or the like as an effective ingredient. A tablet containing such an effective ingredient is generally coated with a film to mask the unpleasant smell or taste of the effective ingredient or ensure stability against light or the like.
However, as the dividable tablet Te of the prior art has a flat upper surface Sa and a flat lower surface Sb, the tablets Te are easily face contacted to each other. As a result, in the step of coating a film on the surface of the tablet Te, there easily occurs such a phenomenon (so called twining) that the tablets Te are adhered to each other.
Similarly, as the two areas R1 and R2 defined by the dividing line Ld on the upper surface Sa of the dividable tablet Tf of the prior art are formed by a plane surface and the lower surface Sb also is formed by a plane surface, the tablets Tf are easily face contacted to each other. Therefore, when the surface of the tablet Tf is coated with a film, the phenomenon (so called twining) that the tablets Tf are adhered to each other easy occurs in the film-coating step.
When the dividable tablets Te and Tf of the prior art are coated with a film, the strength of each of the tablets increases by film coating, whereby greater force is needed to divide the tablets or division readily becomes non-uniform.
A dividable tablet that is free from twining in the film-coating step when the tablet is coated with a film and is easily divided into two is already proposed by Japanese Patent Application Laid-open No. Hei 8-53345.
FIGS. 15A to 15C are schematic diagrams of an example of a dividable tablet disclosed by Japanese Patent Application Laid-open No. Hei 8-53345. FIG. 15A is a plan view, FIG. 15B is a bottom view and FIG. 15C is a side view.
A dividing line Ld is formed in this dividable tablet Tg on an upper surface Sa along a center line thereof, two areas R1 and R2 defined by the dividing line Ld on the upper surface Sa have an inclined plane surface from lines Ld2 and Ld2 which are the borders of the dividing line Ld toward the periphery of the tablet so that the thickness of the tablet increases toward the periphery of the tablet, and the lower surface Sb of the tablet Tg has such convexity that a center portion C is higher than a peripheral portion E.
Since the lower surface Sb of this dividable tablet Tg has such convexity that the center portion C is higher than the peripheral portion E, the tablets Tg are point contacted to each other rather than face contacted to each other in many cases. Therefore, twining hardly occurs in the film-coating step.
To divide the tablet Tg into two, a pharmacist, a patient or the like holds the two areas R1 and R2 directly with his fingers and divides it into two along the dividing line Ld. Alternatively, the tablet Tg can be divided into two by pressing it down from above.
FIGS. 16A to 16C are schematic diagrams of another example of a dividable tablet disclosed by Japanese Patent Application Laid-open No. Hei 8-53345. FIG. 16A is a plan view, FIG. 16B is a bottom view and FIG. 16C is a side view.
A dividing line Ld is formed in this dividable tablet (upper KARATE shape and lower standard concave tablet) Th on an upper surface Sa along a center line thereof, two areas R1 and R2 defined by the dividing line Ld on the upper surface Sa have such concavity that the thickness thereof increases from lines Ld2 and Ld2 which are the borders of the dividing line Ld toward the periphery E of the tablet Th, and the lower surface Sb of the tablet Th has such convexity that a center portion C is higher than a peripheral portion E.
Since the lower surface Sb of this dividable tablet Th has such convexity that the center portion C is higher than the peripheral portion E like the dividable tablet Tg, the tablets Th are point contacted to each other rather than face contacted to each other.
Further, as the two areas R1 and R2 defined by the dividing line Ld on the upper side have convexity to eliminate a flat portion from the surfaces of the tablet Th, twining more hardly occurs in this dividable tablet Th than the dividable tablet Tg during the film-coating step.
To divide the tablet Th into two, a pharmacist, patient or the like holds the two areas R1 and R2 directly with his fingers and divides it into two along the dividing line Ld. Alternatively, the tablet Th can be divided into two by pressing it down from above.
The tablet is generally contained in a press-through pack (generally called xe2x80x9cPTPxe2x80x9d) to protect it from moisture, dust, mold, bacteria and the like while it is preserved.
FIG. 17 is a sectional view showing a typical example of the press-through pack.
This press-through pack 101 comprises a storage body 102 and a sealing sheet 103.
The storage body 102 is made from a synthetic resin such as polyvinyl chloride, polypropylene or cyclic polyolefin and has a plurality of storage recessed portions 102b, . . . , 102b which are formed according to the shape of the tablet T and connected by plate portions 102a, . . . , 102a. 
The sealing sheet 103 consists of a base 105 made of aluminum foil or the like and an adhesive layer 104 formed on one side of the base 105.
The press-through pack 101 is constituted such that the adhesive layer 104 of the sealing sheet 103 is bonded to the plate portions 102a, . . . , 102a of the storage body 102 to seal the storage body 102 with the sealing sheet 103 while the tablets T, . . . , T are each contained in the storage recessed portions 102b, . . . 102b. 
When projecting portions 102c, . . . , 102c which are the exterior sides of the storage recessed portions 102b, . . . 102b of the storage body 102 are each pressed, portions r1, . . . , r1 of the sealing sheet 103 sealing the storage recessed portions 102b, . . . , 102b are broken by the tablets T, . . . , T contained in the storage recessed portions 102b, . . . , 102b so that the tablets T, . . . , T can be taken out from the press-through pack 101 one by one.
When the dividable tablets Te or Tf are contained in this press-through pack 101, a pharmacist or a patient generally breaks the sealing sheet 103 by the dividable tablets Te or Tf contained in the storage recessed portions 102b, . . . , 102b to take out the dividable tablets Te or Tf one by one and then divides the dividable tablets Te or Tf into two with his fingers if necessary.
Japanese Patent Application Laid-open No. Hei 8-53345 teaches that when the dividable tablets Tg or Th are contained in the press-through pack 101, the dividable tablets Tg or Th can be each divided into two before they are taken out from the press-through pack 101.
Thus, if the dividable tablets Tg or Th are each divided into two before they are taken out from the press-through pack 101, it is not necessary to hold the dividable tablet Tg or Th with fingers when it is divided into two. Thereby, when the dividable tablet Tg or Th is divided into two, the tablet Tg or Th is not contaminated with fingers.
However, it cannot be said that such problems that it is difficult to divide the dividable tablet Tg or Th into two by applying force from above in a vertical direction and that defective products are easily produced in the tabletting step or the coating step are completely solved. Further, when the dividable tablet Tg or Th is pneumatically transported from one place to another or transported in the press-through pack 101 or a bottle, it is easily chipped during transportation.
For example, when the dividable tablet Tg is divided by applying force from above in a vertical direction (see FIG. 18A), as shown in FIG. 18B, since the edge portion Pe of the upper surface Sa of the tablet Tg is pointed, force is concentrated on the pointed edge portion Pe and the edge portion Pe may be crushed or chipped.
The dividable tablet Tg has such a problem that the pointed edge portion Pe thereof is easily capped in the tabletting step.
Since the two areas R1 and R2 defined by the dividing line Ld on the upper surface Sa of the tablet Tg are flat, when the area R1 of one tablet Tg is contacted to the area R1 of another tablet Tg, the area R1 of one tablet Tg is contacted to the area R2 of another tablet, or the area R2 of one tablet Tg is contacted to the area R2 of another tablet Tg, the tablet Tg is face contacted to the tablet Tg. In this case, since the tablets Tg are face contacted to each other, such a problem that twining occurs in the coating step cannot be solved yet.
Since the edge portion Pe on the upper surface Sa of the tablet Tg is pointed, core erosion (phenomenon in which original tablet abrades), edge chipping (phenomenon in which edge portion is chipped) or the like readily occurs by collision between the tablets Tg.
When the tablet Tg is pneumatically transported from one place to another, there are such problems that the edge portion Pe on the upper surface Sa of the tablet Tg may be chipped by collision between the tablets Tg or collision between the tablet Tg and a transport pipe during pneumatically transportation and that the edge portion Pe on the upper surface Sa of the tablet Tg may be chipped or the sealing sheet 103 is broken with the edge portion Pe by collision between the pointed edge portion Pe and the storage body 102 or the sealing sheet 103 due to vibration produced during transportation when the tablet Tg is transported in the press-through pack 101.
When the tablets Tg are contained in a bottle, the edge portion Pe may be chipped by collision between the tablets Tg or collision between the tablet Tg and the bottle due to vibration produced during transportation.
Further, when the tablet Tg is contained in the press-through pack 101 and the upper surface Sa having the dividing line Ld of the tablet Tg contained in the storage recessed portion 102b of the storage body 102 of the press-through pack 101 faces the sealing sheet 103 (see the tablet Tg contained in the storage recessed portion 102a on the right side of FIG. 19A), the tablet Tg can be divided into two easily by pressing the protuberant center portion of the lower surface Sb of the tablet Tg through a projecting portion 102c which is the exterior surface of the storage recessed portion 102b of the storage body 102 of the press-through pack (see the tablet Tg contained in the storage recessed portion 102b on the right side of FIG. 19B). Conversely, when the upper surface Sa having the dividing line Ld of the tablet Tg contained in the storage recessed portion 102b of the storage body 102 of the press-through pack 101 faces the storage body 102 (see the tablet Tg contained in the storage recessed portion 102b on the left side of FIG. 19A), relatively large force is needed to divide the tablet Tg into two because, when the projecting portion 102c which is the exterior surface of the storage recessed portion 102b of the storage body 102 of the press-through pack 101 is pressed with a finger, the two areas R1 and R2 defined by the dividing line Ld on the upper surface Sa of the tablet Tg take the same form as the storage recessed portion 102b crushed substantially into a V shape when seen from side and the finger.
Therefore, to make it easy to divide the tablet Tg into two before taking out the tablet Tg from the storage recessed portion 102b of the storage body 102 of the press-through pack 101, as shown on the right side of FIG. 19A, the directions of all the tablets Tg to be contained in the storage recessed portions 102b of the storage body 102 of the press-through pack 101 must be limited such that the upper surfaces Sa having the dividing line Ld of the tablets Tg face the sealing sheet 103. It is extremely difficult to contain all the tablets in the storage recessed portions 102b of the storage body 102 of the press-through pack 101 while they are limited to a certain direction.
Even if all the tablets Tg can be contained in the storage recessed portions 102b of the storage body 102 of the press-through pack 101 while they are limited to a certain direction, when the tablets Tg are each contained in the storage recessed portions 102 in such a manner that the upper surfaces Sa having the dividing line Ld of the tablets Tg face the sealing sheet 103, the pointed edge portion Pe faces the sealing sheet 103, whereby the sealing sheet 103 is easily broken by the pointed edge portion Pe without being pressed with a finger.
When the dividable tablet Th is to be divided by applying force from above in a vertical direction like the dividable tablet Tg (see FIG. 20A), there are such problems that force is concentrated on the pointed edge portion Pe and the edge portion Pe is thereby crushed or chipped as the edge portion Pe of the upper surface Sa of the tablet Th is pointed, thereby making it difficult to divide the dividable tablet Th (see FIG. 20B) and that the pointed edge portion Pe is easily capped in the tabletting step.
Since the edge portion Pe of the upper surface Sa of the tablet Th is pointed, core erosion (phenomenon in which original tablet abrades) or edge chipping (phenomenon in which edge portion is chipped) readily occurs due to collision between the tablets Th in the coating step like the dividable tablet Tg.
Further, when the tablets Th are pneumatically transported from one place to another, the edge portion Pe of the upper surface Sa of the tablet Th may be chipped by collision between the tablets Th or collision between the tablet Th and a transport pipe during transportation. When the tablets Th are transported in the press-through pack 101, the edge portion Pe of the upper surface Sa of the tablet Th may be chipped by their collision with the storage body 102 or the sealing sheet 103, or the sealing sheet 103 may be broken by the edge portion Pe due to vibration produced during transportation. When the tablets Th are contained in a bottle, the edge portion Pe may be chipped by collision between the tablets Th or collision between the tablet Th and the bottle due to vibration produced during transportation.
Further, when the tablets Th are contained in the press-through pack 101 and the upper surface Sa having the dividing line Ld of the tablet Th contained in the storage recessed portion 102b of the storage body 102 of the press-through pack 101 faces the sealing sheet 103 (see the tablet Th contained in the storage recessed portion 102b on the right side of FIG. 21A), the tablet Th can be easily divided into two by pressing the protuberant center portion of the lower surface Sb of the tablet Th through the projecting portion 102c which is the exterior surface of the storage recessed portion 102b of the storage body 102 of the press-through pack 101 (see the tablet Th contained in the storage recessed portion 102b on the right side of FIG. 21B). Conversely, when the upper surface Sa having the dividing line Ld of the tablet Th contained in the storage recessed portion 102b of the storage body 102 of the press-through pack 101 faces the storage body 102 (see the tablet Th contained in the storage recessed portion 102b on the left side of FIG. 21A), relatively large force is needed to divide the tablet Th into two because, when the projecting portion 102c which is the exterior surface of the storage recessed portion 102b of the storage body 102 of the press-through pack 101 is pressed with a finger, the two areas R1 and R2 defined by the dividing line Ld on the upper surface Sa of the tablet Th take the same form as the storage recessed portion 102b crushed substantially into a V-shape when seen from side and the finger.
In the case of the tablet Th, since the two areas R1 and R2 defined by the dividing line Ld on the upper surface Sa have concavity, the tablets Th are not face contacted to each other unlike the dividable tablet Tg and hence, twining more rarely occurs in the coating step than the dividable tablet Tg. However, since the two areas R1 and R2 defined by the dividing line Ld on the upper surface Sa of the tablet Th have concavity, when the tablet Th is not divided along the dividing line Ld, such a phenomenon that the tablet Th is divided into two in the vicinity of the dividing line Ld in either one of the two areas R1 and R2 readily occurs (see a crack R11 of FIG. 20B).
Further, when the dividable tablet contained in the press-through pack is divided while it is contained in the press-through pack, since the press-through pack of the prior art is produced based on the condition that the tablets are taken out one by one, the tablets divided into two must be taken out from the storage recessed portions 102 one by one, thereby making it troublesome to take out the divided tablets from the press-through pack.
The present invention has been made to solve the above problems, and therefore has an object to provide a dividable tablet which can be divided into two easily and accurately without limiting the direction of the upper surface or lower surface of the tablet, is hardly chipped during its production, pneumatically transportation and/or conveyance and eliminates such a problem as twining even when it is coated with a film.
It is another object of the present invention to provide a press-through pack which enables a pharmacist, patient or the like to divide a dividable tablet easily without touching it with his finger and to take out divided tablets at a time easily and simply.
According to a first aspect of the present invention, there is provided a dividable tablet in which a dividing line is formed on the upper surface of the tablet along a center line thereof, ridgelines located on an inner side of the peripheral portion of the tablet and surrounding the dividing line are each formed in two respective areas defined by the dividing line on the upper surface of the tablet, the lower surface of the tablet gradually rises from the peripheral portion of the tablet toward a center portion thereof, and areas around the two ridgelines are each formed by a convex surface.
In this dividable tablet, when a ridgeline is formed in the two areas defined by the dividing line on the upper surface of the tablet, the areas around the two ridgelines are each formed by a convex surface to eliminate a pointed edge portion from the upper surface of the tablet. Therefore, when force is applied to the tablet from above in a vertical direction, the tablet can be divided into two nicely along the dividing line without being chipped. In addition, the tablet is hardly chipped in the tabletting step, during pneumatically transportation and when carried in a press-through pack or a bottle.
Since a pointed edge portion is eliminated from the upper surface of the tablet, core erosion or edge chipping hardly occurs in the coating step.
Since a pointed edge portion is eliminated from the upper surface of the tablet, when the tablet is contained in the storage recessed portion of the press-through pack, there hardly occurs an accident that the sealing sheet is broken by the tablet without being pressed with a finger.
According to a second aspect of the present invention, there is provided a dividable tablet, wherein the two areas defined by the dividing line on the upper surface of the tablet from lines which are the borders of the dividing line to the two ridgelines are each formed by a convex surface.
The xe2x80x9cconvex surfacexe2x80x9d of each of the two areas from the lines which are the borders of the dividing line to the two ridgelines is a gently rising surface.
Stated more specifically, the surface of each of the two areas is a gently rising surface as a whole with the curvature thereof increasing continuously from the lines which are the borders of the dividing line toward the ridgelines.
Since the lower surface of this dividable tablet gradually rises from the peripheral portion to the center portion of the tablet, when the upper surface having the dividing line of the tablet contained in the storage recessed portion of the press-through pack faces the sealing sheet, the tablet can be easily divided into two by pressing the protuberant center portion of the lower surface of the tablet with a finger through a projecting portion which is the exterior surface of the storage recessed portion of the storage body of the press-through pack.
Since the areas from the lines which are the borders of the dividing line to the two ridgeline are formed by a convex surface, even when the surface having the dividing line of the tablet contained in the stored recessed portion of the press-through pack faces the storage body, force is applied to the tablet in a direction for opening the dividing line without increasing the strength of the finger because the two areas defined by the dividing line on the upper surface of the tablet have a curved surface corresponding to the shape of the storage recessed portion crushed substantially into a V shape when seen from side and the shape of a finger when the projecting portion which is the exterior surface of the storage recessed portion of the press-through pack is pressed with the finger. Thereby, even when the surface having the dividing line of the tablet contained in the storage recessed portion of the press-through pack faces the storage body, the tablet can be easily divided into two.
Thus, this dividable tablet can be easily divided into two before it is taken out from the press-through pack even when it is contained in the storage recessed portion of the storage body of the press-through pack without limiting the direction of the tablet.
Since the dividable tablet has two convex surfaces on the upper side and one convex surface on the lower side, the tablets are not face contacted to each other but point contacted to each other. Thereby, twining hardly occurs in the coating step.
According to a third aspect of the present invention, there is provided a dividable tablet, wherein the dividing line is formed as a groove deeper than the upper surface of the peripheral portion of the tablet.
The term xe2x80x9cdeep groovexe2x80x9d as used herein means a groove whose deepest portion is located below the peripheral portion of the upper surface of the tablet.
More specifically, the distance in a vertical direction from the apex of the bottom surface of the tablet to the deepest portion of the dividing line is shorter than the distance in a vertical direction from the apex of the bottom surface of the tablet to the upper surface of the peripheral portion of the tablet.
Since the dividing line of this dividable tablet is formed deeper than the dividing line of an ordinary dividable tablet, the tablet can be divided nicely along the dividing line.
According to a fourth aspect of the present invention, there is provided a dividable tablet, wherein the dividing line of the dividable tablet is a V-shaped groove or U-shaped groove.
The term xe2x80x9cV-shaped groovexe2x80x9d as used herein means a V-shaped groove or a substantially V-shaped groove. The xe2x80x9csubstantially V-shaped groovexe2x80x9d includes, for example, a V-shaped groove having an area around the apex thereof which is formed round or like the apex of a parabola (a curve of secondary degree) or a curved portion near the apex which is formed polygonal with bents.
The term xe2x80x9cU-shaped groovexe2x80x9d as used herein means a U-shaped groove or a substantially U-shaped groove. The xe2x80x9csubstantially U-shaped groovexe2x80x9d includes, for example, a U-shaped groove having a curved portion that is formed polygonal with bents.
The surface forming the dividing line of the dividable tablet is formed flat or concave and different in shape from the two convex areas from the lines which are the borders of the dividing line to the ridgelines.
Since the dividing line is a V-shaped groove or U-shaped groove, the thickness of the tablet from the deepest portion of the dividing line to the lines which are the borders of the dividing line increases almost uniformly in the case of the V-shaped groove. However, in the case of a U-shaped groove, the thickness of the tablet gradually increases from the deepest portion of the dividing line toward the lines which are the borders of the dividing line within the area of the dividing line and sharply increases in the vicinity of each of the lines which are the borders of the dividing line.
Since the two areas from the lines which are the borders of the dividing line to the ridgelines have a convex surface, the thickness of the tablet sharply increases in the vicinity of each of the lines which are the borders of the dividing line in directions from these lines to the ridgelines.
Thus, changes in the thickness of this dividable tablet within the area of the dividing line are made greatly different from changes in the thickness of the tablet in the vicinity of each of the lines which are the borders of the dividing line in directions from these lines to the ridgelines, the thickness of the tablet is sharply increased in the vicinity of each of the lines which are the borders of the dividing line in directions from these lines to the ridgelines, and force applied to the tablet from the outside per unit volume is made large within the area of the dividing line and made smaller in the vicinity of each of the lines which are the borders of the dividing line in directions from these lines to the ridgelines than force applied to the tablet from the outside per unit volume within the area of the dividing line. Therefore, this tablet can be divided into two nicely along the dividing line.
According to a fifth aspect of the present invention, there is provided a dividable tablet, wherein line portions which are the borders of the dividing line are located at positions above the upper surface of the peripheral portion of the tablet.
The xe2x80x9clines which are the borders of the dividing linexe2x80x9d mean two lines which are the borders of the dividing line.
The xe2x80x9cpositions above the upper surface of the peripheral portion of the tabletxe2x80x9d means, more specifically, positions on the two surfaces from the lines which are the borders of the dividing line to the two ridgelines.
When the dividing line is made large (the depth of the dividing line is made large), the dividable tablet can be easily divided into two. However, when the dividing line is formed deep in a vertical direction from the upper surface of the tablet to make the dividing line large (increase the depth of the dividing line), the mechanical strength of the tablet lowers in the area of the dividing line. Therefore, there is such a problem that the tablet may be divided into two of itself even when it is not intended to divide it into two.
The lines which are the borders of the dividing line are not formed on the upper surface of this dividable tablet but formed at positions above the upper surface of the peripheral portion of the tablet. Therefore, the dividing line can be made large (the depth of the dividing line is increased) without forming the dividing line deep in a vertical direction from the upper surface of the tablet.
Thereby, the dividing line can be made large (the depth of the dividing line is increased) without reducing the mechanical strength of the tablet in the area of the dividing line as in the case where the dividing line is formed deep in a vertical direction of the tablet from the upper surface of the tablet. Therefore, there can be obtained a dividable tablet that can be easily divided into two and is not divided into two of itself when it is not intended to divide it into two.
According to a sixth aspect of the present invention, there is provided a dividable tablet, wherein the areas from the two ridgelines on the upper surface of the tablet to the peripheral portion of the tablet are each a steep slope.
The areas from the two ridgelines on the upper side of the tablet to the peripheral portion of the tablet are each formed by a steep slope, and the areas from the lines which are the borders of the dividing line on the upper surface of the tablet to the ridgelines are each formed by a more gently rising surface than the areas from the two ridgelines to the peripheral portion of the tablet. Therefore, when force is applied to the tablet from above in a vertical direction, force is easily applied in a direction for opening the dividing line. Thereby, the tablet can be divided nicely along the dividing line with small force.
According to a seventh aspect of the present invention, there is provided a dividable tablet, wherein the steep slope has a plane or convex surface when it is seen from side.
In this dividable tablet, areas around the two ridgelines formed on the upper surface of the tablet do not have a pointed edge portion but a convex surface. In addition, when force is applied to the tablet from above in a vertical direction, to make it easy to apply force to the tablet in a direction for opening the dividing line, the steep slope of the area from the ridgeline on the upper surface of the tablet to the peripheral portion of the tablet may have a plane or convex surface and not a concave surface when seen from side if the area from the line which is the border of the dividing line on the upper surface of the tablet to the ridgeline can be formed by a gently rising surface.
Therefore, it may be determined from the design of the tablet whether the steep slope of the area from the ridgeline on the upper surface of the tablet to the peripheral portion of the tablet should be formed by a plane or convex surface. Consequently, the shape of the tablet can be determined based on the medical virtue, efficacy and effect of the dividable tablet so that the shape of the tablet can impress doctors, pharmacists, patients and the like.
According to an eighth aspect of the present invention, there is provided a dividable tablet, wherein areas around points of intersection between the dividing line and the peripheral portions of the tablet are chamfered into two convex surfaces sandwiching the dividing line.
In this dividable tablet, since the areas around points of intersection between the dividing line and the peripheral portions of the tablet are chamfered into two convex surfaces sandwiching the dividing line, the tablet is more hardly chipped.
The above dividable tablets of any one of the first to eighth aspects of the present invention may be a bare tablet or coated with a film, sugar or the like.
The above dividable tablets of any one of the first to eighth aspects of the present invention may contain a vehicle, binder and disintegrator and optionally lubricant in addition to effective ingredients. Further, they may be formulated by adding a sweetener, coloring agent, seasonings, antioxidant and the like.
The above dividable tablets can be produced by compression molding methods.
The compression molding methods include one in which mixture powders are tabletted directly and one in which a granulated product having a predetermined particle diameter and particle size distribution is produced from powders by a dry or wet process and formed into granulated powders or fine powders through a drying step and a sizing step, a slight amount of a lubricant is added to the powders, and the mixture is compression molded into a tablet.
Since the above dividable tablets of any one of the first to eighth aspects of the present invention have no pointed portion, sticking, lamination or capping hardly occurs in the tabletting step. Therefore, not only a single eccentric tabletting machine but also a rotary tabletting machine can be used to produce the above dividable tablets by continuous tabletting.
The lubricant may be added to the effective ingredient, the vehicle or the like, and a mixture of the effective ingredient, the vehicle and the lubricant may be tabletted (this tablet production method is called xe2x80x9cinternal lubricating methodxe2x80x9d). Alternatively, the lubricant is not added to the effective ingredient, the vehicle or the like but sprayed onto the surface of a punch or die, and a mixture of the effective ingredient, the vehicle and the like may be tabletted using the punch or die having a lubricant layer on the surface (this tablet production method is called xe2x80x9cexternal lubricating methodxe2x80x9d).
Various commonly used coating methods may be used. For example, pan (or drum) coating, flow coating or the like may be used.
The thickness of a coating film is not particularly limited but is preferably in the range of 10 to 50 xcexcm.
Various vehicles may be used without restriction. Any known vehicles such as saccharides exemplified by lactose, mannitol, saccharose and glucose, starches exemplified by potato starch, corn starch and partly xcex1-ed starch, inorganic salts exemplified by precipitated calcium carbonate, calcium phosphate and sodium chloride, and crystal cellulose may be used.
The vehicle is generally contained in an amount of 10 to 95 parts by weight in one tablet.
Various binders may be used without restriction. Any known binders such as partly saponified polyvinyl alcohol, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, polyvinyl pyrrolidone, pullulan, methyl cellulose, Arabian rubber and starches may be used.
The binder is generally contained in an amount of 0.5 to 5 parts by weight in one tablet.
Various disintegrators may be used without restriction. Any known disintegrators such as crospovidone, hydroxypropyl cellulose having a low degree of substitution, croscarmellose sodium, carboxymethyl cellulose, carboxymethyl cellulose calcium, carboxymethyl starch sodium, partly xcex1-ed starch and hydroxypropyl starch may be used, out of which crospovidone, hydroxypropyl cellulose having a low degree of substitution and croscarmellose sodium are preferred.
The disintegrator is contained in an amount of 1 to 15 parts by weight in one tablet.
Illustrative examples of the lubricant used for tabletting include magnesium stearate, calcium stearate, zinc stearate and stearic acid, talc, hydrogenated vegetable oil and the like, out of which magnesium stearate and calcium stearate are preferred.
The lubricant is generally contained in an amount of 0.01 to 5 parts by weight in one tablet.
According to a ninth aspect of the present invention, there is provided a press-through pack which comprises a storage body having a plurality of storage recessed portions interconnected by plate portions and a sealing sheet having a base and an adhesive layer formed on one side of the base. While the above tablets of any one of the first to eighth aspects of the present invention are each contained in the plurality of storage recessed portions of the storage body, the adhesive layer of the sealing sheet and the plate portions of the storage body are bonded together to seal the storage body with the sealing sheet. The sealing sheet for sealing the storage recessed portions is broken without the rise or peel-off of the adhesive layer of the sealing sheet from the plate portion of the storage body when a projecting portion which is the exterior portion of the storage recessed portion containing the above dividable tablet of any one of the first to eighth aspects of the present invention is pressed with a finger so that the above dividable tablet of any one of the first to eighth aspects of the present invention can be taken out. The sealing sheet is bonded to the plate portions of the storage body so that it can be easily separated from the storage body.
Explaining in more detail the above expression xe2x80x9cbonded to the plate portions of the storage body so that it can be easily separated from the storage bodyxe2x80x9d, this means that the sealing sheet is bonded such that when part of the sealing sheet of the press-through pack is turned up, it can be easily separated from the plate portion of the storage body without being broken.
In this press-through pack, at least one of the above dividable tablets of the first to eighth aspects of the present invention may be contained in any one of the storage recessed portions of the storage body.
The dividable tablet contained in any one of the storage recessed portions of the storage body may be contained in such a manner that the surface having the dividing line of the dividable tablet contained in the storage recessed portion faces the storage body or the opposite surface faces the storage body. Further, both dividable tablets the surface having the dividing line of which faces the storage body and dividable tablets the opposite surface of which faces the storage body may be each contained in the storage recessed portions of the storage body arbitrarily.
The bonding strength between the sealing sheet and the plate portion of the storage body of this press-through pack is preferably 0.9 N/15 mm in width to 3.1 N/15 mm in width, more preferably 1.9 N/15 mm in width to 2.7 N/15 mm in width when a T peel test is carried out at a peel rate of 200 mm/min.
When a T peel test is carried out at a peel rate of 100 mm/min, the bonding strength is preferably 4.2 N/15 mm in width to 7.0 N/15 mm in width, more preferably 4.8 N/15 mm in width to 6.5 N/15 mm in width.
The unit xe2x80x9cN/15 mm in widthxe2x80x9d as used herein means peel strength when the storage body and the sealing sheet are bonded together, a bonding portion between the storage body and the sealing sheet is cut to a width of 15 mm and a T peel test is made on this cut piece as a test sample.
The term xe2x80x9cT peel testxe2x80x9d as used herein means a test based on JIS K6845.
Within the above range, when the dividable tablet is taken out by breaking the portion sealing the storage recessed portion of the sealing sheet by pressing the projecting portion which is the exterior surface of the storage recessed portion containing the dividable tablet of the storage body toward the sealing sheet with a finger, the sealing sheet can be separated from the storage body without the rise or peel-off of the adhesive layer of the storage body from the sealing sheet at a bonding portion between the adhesive layer of the sealing sheet and the plate portion of the storage body outside the storage recessed portion (so-called pocket) from which the dividable tablet is taken out of the sealing sheet. Also, when the sealing sheet is peeled and turned up, the sealing sheet can be separated from the storage body without being broken.
In contrast to this, below the above range, though the sealing sheet can be separated from the storage body without being broken when the sealing sheet is peeled and turned up, when the dividable tablet is taken out by breaking the sealing sheet by pressing the projecting portion which is the exterior portion of the storage recessed portion containing the dividable tablet of the storage body toward the sealing sheet with a finger, the sealing sheet peels off or rises from the storage body at the bonding portion between the adhesive layer of the sealing sheet and the plate portion of the storage body outside the storage recessed portion from which the dividable tablet is taken out of the sealing sheet.
Above the above range, when the dividable tablet is taken out by breaking the sealing sheet by pressing the projecting portion which is the exterior portion of the storage recessed portion containing the dividable tablet of the storage body toward the sealing sheet with a finger, the sealing sheet does not peel off or rise from the storage body at the bonding portion between the adhesive layer of the sealing sheet and the plate portion of the storage body outside the storage recessed portion from which the dividable tablet is taken out. However, it is difficult to peel and turn up the sealing sheet and separate it from the storage body. If the sealing sheet is forcedly separated from the storage body, it is partially broken disadvantageously.
The term xe2x80x9cadhesive componentxe2x80x9d as used herein means an adhesive used for heat sealing or cold sealing.
The term xe2x80x9cbonding strength reducing componentxe2x80x9d means a component having the function of reducing the bonding strength of the adhesive component, such as an adhesive having low bonding strength which is generally used as a release agent, filler or the like, as exemplified by a resin used as a release agent or the like, such as a silicone resin or fluororesin. When the storage body is made from polyvinyl chloride, an acrylic resin is used as the bonding strength reducing component.
Illustrative examples of the filler include fine powders of silicon oxide, magnesium silicate, titanium dioxide, zinc oxide, calcium carbonate, alumina, talc and the like.
In this press-through pack, by adding an appropriate amount of a bonding strength reducing component to an adhesive component, the bonding strength of an adhesive is controlled to such a level that the sealing sheet can be separated from the storage body without the peel-off or rise of the sealing sheet from the storage body outside the area of the storage recessed portion (so called xe2x80x9cpocketxe2x80x9d) from which a solid is taken out when the solid is taken out by breaking part of the sealing sheet by pressing the projecting portion which is the exterior surface of the storage recessed portion containing the dividable tablet of the storage body toward the sealing sheet with a finger and that the sealing sheet can be separated from the storage body without being broken when part of the sealing sheet is peeled off from the storage body and turned up.
In the press-through pack of the present invention, the adhesive layer of the sealing sheet may be formed on part of the surface of one side of the sealing sheet.
Various methods are conceivable for partial coating. If the dividable tablets contained in the storage recessed portions of the storage body can be completely sealed, an adhesive may be applied to the surface of a side facing the storage body of the sealing sheet reticulately, linearly or both.
This press-through pack is partially coated with an adhesive to control the bonding strength of the adhesive so that the sealing sheet can be separated from the storage body without the peel-off or rise of the sealing sheet from the storage body outside the so-called pocket when a solid is taken out by breaking part of the sealing sheet by pressing the projecting portion which is the exterior surface of the storage recessed portion containing the dividable tablet with a finger and the sealing sheet can be separated from the storage body without being broken when part of the sealing sheet is peeled off from the storage body and turned up.
Therefore, the dividable tablets contained in this press-through pack can be taken out from the storage recessed portions one by one or at a time by separating the sealing sheet from the storage body.
Further, since the above dividable tablets of any one of the first to eighth aspects of the present invention are each contained in the storage recessed portions of the press-through pack, even when the dividable tablets are contained in the storage recessed portions without limiting the directions of the dividable tablets, the dividable tablets can be each divided into two easily and simply before they are taken out from the storage recessed portions by pressing the projecting portions which are the exterior portions of the storage recessed portions containing the dividable tablets with a finger.
Therefore, before the dividable tablet is taken out from the storage recessed portion, the dividable tablet can be divided into two easily and simply and then the divided tablet can be taken out from the storage recessed portion.
Further, before the dividable tablets contained in the storage recessed portions of the press-through pack are taken out from the storage recessed portions, the dividable tablets can be each divided into two easily and simply and then the divided tablets contained in the press-through pack can be taken out from the storage recessed portions at a time by separating the sealing sheet from the storage body.